Crystal is a solid whose atoms are arranged in a “highly ordered” repeating pattern. These patterns are called crystal lattices. If an object has its atoms arranged in one of seven crystal lattice patterns, then that object is a crystal. There are seven crystal lattice patterns: cubic, tetragonal, rhombohedral (or trigonal), hexagonal, orthorhombic, monoclinic, and triclinic. Each is distinguished by the geometric parameters of its unit cell, the arrangement of atoms that is repeated throughout the solid to form the crystal object we can see and feel.